Most cosmetic products include simultaneously water soluble and oil soluble compounds, which should be mixed together and which cannot separate into two or more phases, since otherwise the action is no longer so effective as in mixed form. Therefore, they should form an emulsion. The formation of an emulsion often requires the use of an emulsifier.
Up to now a lot of synthetic emulsifiers have been used. Among them, emulsifier based on alcohols, fat acids or ethoxylated esters are usually employed. The use of such substances can be harmful for human skin and their viscosity is sometimes too high. The advantage of using a functional ingredient derived from olive oil is due to the high similarity of fatty acids contained in olive oil with the acids in the skin. This is the reason why the product has a high compliance with the human skin, good absorption and a light skin feeling.
A few natural emulsifiers have been tested, but either they are not so effective as the synthetic ones or they should be used in large amounts.